<template>
    <div>
      <router-link
        tag="div"
        to="/"
        class="header-abs"
        v-show="showAbs"
      >
        <div class="iconfont header-abs-back">&#xe624;</div>
      </router-link>
      <div
        class="header-fixed"
        v-show="!showAbs"
        :style="opacityStyle"
      >

        <router-link to="/">
          <div class="iconfont header-fixed-back">&#xe624;</div>
        </router-link>
        景点详情
      </div>
    </div>
</template>

<script>
    export default {
        name: "DetailHeader",
        data(){
          return {
            showAbs:true,
            opacityStyle:{
              opacity:0
            }
          }
        },
      methods:{
          handleScroll(){
            const top = document.documentElement.scrollTop
            if(top>60){
              let opacity = top/140
              opacity=opacity>1?1:opacity
              this.opacityStyle={
                opacity
              }
             this.showAbs = false
            }else{
              this.showAbs = true
            }
          }
      },
        activated(){
          window.addEventListener('scroll',this.handleScroll)
        },
        deactivated(){
          window.removeEventListener('scroll',this.handleScroll)
        }
    }
</script>

<style lang="stylus" scoped>
  @import '~styles/varibles.styl'
  .header-abs
    position absolute
    top:.2rem
    left:.2rem
    width:.8rem
    height:.8rem
    border-radius .4rem
    text-align center
    line-height .8rem
    background rgba(0,0,0,.8)
    .header-abs-back
      color: #fff
      font-size .4rem
  .header-fixed
    z-index 2
    position fixed
    top: 0
    left: 0
    right: 0
    height:$headerHeight
    line-height $headerHeight
    text-align center
    color #fff
    background $bgColor
    font-size .32rem
    .header-fixed-back
      position absolute
      left: 0
      top: 0
      width:.64rem
      font-size .4rem
      text-align center
      color #fff
</style>
